Steam boiler regulator



Filed Aug. 25, 1939 i R .9 R R om w m EW .O VS T mE m M A 3 .l a 3 uw @w/AZ/vwg 3 ,um ,///vlz 3 um n 1 w 7 r Z @I n0 7 7 001 0U 5 7 mmv M c C u f ...l l0 f O 0I AT V 3 A: l 0 4 Z 6 @155554444 m flou. Z I QU al.

Patented June 17, 1941 UNITED STATES PATENT oFF-ice STEAM BOLER REGULATOR James W. Harrie, Oakland, Calif., assignor to Westinghouse Pacific Coast Brake Company,A l Emeryville, Calif., a corporation of California u Application August 25, 1939, serial'liNe. .291,908

(o1. 23e-21) e 1 claim.

This invention relates to furnace'control systems for regulating the supply of fluid fuel, such as gas orl oil, to the burner of a furnace for heating a steam boiler, the present applicationbeing a continuation in part of my prior application filed in the United States Patent Oce on January 6, 1938, Serial No. 183,670, which has matured into Patent No. 2,176,132.

In the operation of a boiler having a low water cut-01T valve by operation of which fluid fuel supplied to the burners is automatically shut `olf when the water level in the boiler falls to a dangerously low point, the use of a steam pressure actuated controller for automatic regulation of the boiler fire in accordance with boiler pressure is sometimes accompanied by an undesirable condition when the water level is restored and the cut-olf valve in the fuel supply line is again opened. When the fuel supply is shut off by operation of the low water cut-off valve, the steam pressure naturally falls, causing the steam pressure actuated controller to move toward its full fire position, and as a result, when the normal water level is restored andthe low water cut-off valve reestablishes the supply of fuel, the fuel valve which is controlledv by the steam pressure actuated controller will be in a wide open position. The fuel entering the furnace suddenly through this wide open valve may then create an explosive increase in the fire which is dangerous and detrimental to the furnace.

The principal object of this invention is to provide an improved regulator device adapted for association with a boiler having the above described equipment, which regulator deviceA is automatically responsive to a predetermined reduc-,- tion in the pressure of fuel being supplied .to the boiler furnace for effecting operation ofthe steam pressure actuated controller to a low fire position, so that upon restoration of the normal water level and consequent opening of the low water shut-off valve the controller is initially effective to retard the supply of fuel, with the result that the furnace re is increased gradually andat a safe rate.

Another object of the invention is to provide an auxiliary regulator of the above type, the elements of which are associated in a unitary structure adapted to be mounted in any desired position, and which device includes a manually releasable trigger mechanism adapted for operation to lock the steam actuated controller in its low re position, following a reduction in the supplyv of fuel such as that effected in response to a low water condition.

Other objects and advantages of the invention will be apparentvin the following more detailed description thereof, taken in connection with the accompanying drawing, whereinn Fig. 1 is a fragmentary diagrammatic view, partly in section, of a boiler furnace equipped with a control system embodying the invention; Fig. 2 is an enlarged detail sectional View of the steam actuated controller shown in Fig. 1 and having associated therewithvan auxiliary regulator device constructed in accordance with the invention. y e Y Referring to Fig. 1 of the drawing, there is shown therein afurnace I, which may be of any well known construction and is provided with a Yfire box having a burner for heating a boiler,

not shown. The burner of the furnace is adapted to be supplied with `iiuid fuel, such as gas' or oil, through a supply pipe 3. Air is supplied to' the furnace fire box through an opening controlled by a draft door 5, and the burned gases escape from the re box through a smoke pipe 6, in which is mounted a damper 1 for regulating the rate of W of gas through the smoke pipe.4

Mounted on the furnace I is a steam actuated controller device I0, which `may be'of any suit-` able type operative to regulate the rate of supply of fuel through the supply pipe 3 to the furnace and also to control the draft door 5 and damper l, which device is illustrated in the drawing as havingthe same construction as that disclosed in my UnitedStates Patent 2,147,294, issued on February 14, 1939. According to the present invention,l the steam vactuated controller I0 has associated therewith an auxiliary regulator device I I, which is operative to control operation of the controller device I0 in response to a predetermined reduction in the pressure of fuel supplied through the pipe 3, as hereinafter explained. v l l The furnace I also has associated therewith means responsive to the level of the water in the boiler of the furnace for controlling the supply of water to the boiler and the rate of supply of fuel through the supply pipe 3 to the fire box burner. As illustrated in the drawing, this means may comprise a pressure generator I2 adapted to vary the pressure of fluid in a pipe I 5, a fluid pressure responsive water valve device I4 operative on a predetermined increase in fluid pressure in the pipe I6 to open acommunication through a pipe l5 for supplying water to the boiler, and a fuel shut-olf valve device I 8 responsive to an increase in the pressure of fluid in the pipe I6 to reduce the rate of fuel flow through the supply pipe 3. The steam generator I2 and pressure responsive valve devices I4 and I8, being well known in the art, are not illustrated in detail, but it will be understood that the generator is operative under a low water condition of the boiler to eiect an increase in the pressure of fluid in the pipe I6 above a normal value, and that the valve devices I4 and I8 are operative in accordance with; such increase in fluid pressure to supply water to the boiler and to reduce the supply of fuel to the burner.

As shown in Fig. 2 of the drawing, the steam pressure actuated controller device I comprises i a movable abutment or piston which is movably mounted in a bore formed in a body 2|, and

has secured thereto a piston stem 22 whichex tends through a suitably sealed opening in the end wall of the bore. Referring again toFig. 1, the outer end of the stem 22 is connected by means of a chain 23 with a lever 24, which is pivotally supported by a pin 26 on a bracket 21 carriedl-` by the furnace I. The lever 24has secured'thereto a weight V23V which urges the lever 24 in a clockwise direction about the pin 26v and thus exerts a downward pull through the medi um of the.chain.23.on the piston within the controller. The lever .24 Visconnected by means of a link-30with an a-rm 32vassociated with a valve device 33, whichis interposed. inthe supply 3.,.at a4 point intermediate the valve device I8 and the burner. of the furnace. The valve-device 33 is adapted to reduce the supply of fuelto thesupplyv pipe 3 in response `to upward movement-of the. arm .-32, link 30,. and chain 23 by operation of the controller piston as hereinafter. explained. The` lever.V 24A is, also connected .by means ofY a chain'34 with thedraft door 5, -andv-by.meahs ofV achain 36 with an operating level' 31=controlling the damper 1. A weight 38.is..secured to the free end of the lever 31 for exerting a force-opposingthe pull transmitted-by the controller I0 through the medium of the chain 36, and for biasing the damper toward full `open position as` shown in the drawing.

As shown in Fig. 2 of the drawing, the controller device I0 further-comprises valvef means indicated generally by the reference Vcharacter for regulating the supply Yof yfluid underf pressure to a chamber 4I. at the lower face of the` pistonl 20, andforalso regulating the release of' fluidunder. pressure from that chamber. The

valve means 40- includesav-,body having acham.A ber 42, which -is constantly connected by way of a pipe 43 with a source of wateror other fluid under pressure, and a chamber 44 which is'constantly connected with thechamber 4I by way of a. passage having -aA restricted portion45.0V A ball valve 46 isdisposed in the chamber 421 and is adapted to engage a seatadjacentthechamber 44 to cut olf communication between Ycham-` bers 42 and.44. A spring 48 isprovided inf chamber` 42.for pressing .the ball valves46 toward seat-y ed position. Associated with the. ball-valveis a valve stem 50,. theA lower end of which extends into the chamber 4,4 andhasformed therein a passage Slopeningat a terminal seat formed onthe. stem and engageable` with the `upper surface of the ball valve 46 to prevent now of luidfrom A: coil spring54 is mounted in'thechamber 53 ber' tween a flange 55 on the valve stem 50 and a packing gland forming an end wall of the chamber, which spring is adapted to press the valve stem 50 upwardly, as viewed in the drawing. The passage 5| in the end portion of the valve stem 50 is open to the release chamber 53, and the chamber 53 is in turn constantly connected to a drain pipe 56, which leads to a valve chamber formed in the auxiliary regulator device hereinafter described. The chamber 51 at the upper face of the actuator piston 20 is constantly connected to a drain pipe 58.

For controlling operation of the valve means 40 to effect movement of the piston 20 in accordance with variations in the pressure of the steam inthe boiler, the control device I0 is provided with almovable abutment in the form of a diaphragm 60,-which is clamped between a cover 6| and a body 62 which is disposed above the body 2| and may be secured thereto by suitable means, such as bolts. The diaphragm and cover 6|.deflne a chamber 64 which is` constantly connected byway of a pipe to the boiler associated withthe furnace I shown in Fig. 1 of the drawing. The diaphragm -60 has at the lower face thereofa followerv member 61, which is `urged upwardly againstthe diaphragm in opposition to the pressure of steam in the; chamber 64 bythe force ofaeoil spring E8 interposed betweenthe memberfandaspring seat 69 adjustably supported on athreaded member 10 carried bythe .body- 62. Operatively connected to the `follower member 61is apush rod 15 which extends. through a central aperture formed in the lower spring seat` 69 and through a bore in the member 10 into operative alignment with a lever 12 having one end-pivotally supported by means of ball bearings` 13. on a bracket 14 forming part of the framestructure of the-controller device I0.

The lever 12` has mountedthereon intermediate yits ends an adjusting screw 18, the end of which extends. into a socket formed` infone end of arod 19theotherend of which has a socket y for receiving'theupper end of valve stem 50.

Onthe free end of the` lever 12 is mounted an adjustingcscrew 8| engaging in a socket formed in a spring seat 82, which'has a tubular extension containing. a coil spring 83 that isinterposed between the spring seat 82 and a slidably mounted spring seat 85 whichisin turn pivotally supported on one-arm of abellcrank lever 81 journaled on a lpinll carried by the bracket 14, The. other arm of the bell crank lever 81 is oiTset-and `carries aroller which is'adapted to rideon .an .inclined rod 9| adjustably secured to a vertically disposed rod- 93 by suitable means, includingan `adjusting screw 94 and bracket 96. The rod 93 isadapted to be guided by aroller 98 which is suitably journaled on a pin carried by the bracket 14, .the lower end of the rod being secured to an arm 99 carried by the piston stern` 22. f

According to my invention, the auxiliary regulator device II comprises a frame |00 of polyg onal form -having a bottomportionV |62 on which aresuitably mounted a supply valve assembly |03 and a `drain valve assembly |04, and a casing member |05 which is-secured tothe upper portion of the frame by means of a clamping memberf|01. The member j|01 extends through a suitable aperture V|08 formed in the frame and a similar aperture |09 formed in the casing member` and into a chamber IIO therein which con- Ktains a nut having screw threaded engagement with the clamping member. Suitable mounting lugs H3 havingapertures for receiving bolts are formed on the casing |05.

A flexible diaphragm H2 is interposed between the casing member |05 and a cover plate H5 secured thereto by means of bolts H6, which diaphragm is exposed at the lower side thereof to the chamber H and has formed at the upper side thereof a chamber ||1 communicating by way of a pipe H8 with the fuel supply pipe 3, as shown in Fig. 1, at a point intermediate the cut-off valve device I8 and the valve device 33. Engaging the diaphragm H2 on the lower face thereof is a follower member |20 having guide pins |2| projecting downwardly therefrom through the chamber H0 and outwardly through suitable apertures formed in the casing member |05, and also having a centrally disposed rod |23 which is slidably mounted in a suitable bore formed in the clamping member |01 and has secured to the lowermost end thereof a crosshead member |24. A coil spring |25 is interposed between the follower member |20 and the nut H| for urging the diaphragh H2 upwardly in opposition to the pressure of fuel supplied in the chamber H1.

The crosshead member |24 is disposed at a right angle with respect to the rod |23 and is arranged within the frame |00, one arm of the crosshead member extending into alignment with the supply valve assembly |03 and the other end into alignment with the drain valve assembly |04. The crosshead member has formed thereon a central lug portion |21 which is formed as a clevis and carries a pin |28 from which is hung a vertically disposed latch member |30 having the lowerV end thereof slidably mounted in an opening |3| formed in the lowermost portion |02 of the frame. The latch member |30 has a surface |32 which is adapted to engage the adjacent wall of the opening |3| while the crosshead member |34 is positioned as shown in Fig. 2, and is provided with a notch or recess |33 adapted to interlock with the portion |02 of the frame upon upward movement of the crosshead member, as hereinafter explained, under the force exerted by a spring |34 attached to the frame and bearing against the latch member. The latch member 30 has a handle portion |35 for enabling manual release thereof.

The supply valve assembly |03 comprises a body |38 having a screw threaded end |39 extending through a suitable aperture formed in the frame |00 and secured thereto by means of a clamp nut |40, and. having formed therein a valve chamber |4| which communicates by way of a pipe |42 with the chamber 4| of the controller device |0, and which is closed at the upper end by means of a plug element |43 having screw threaded connection with the portion |39. Disposed in the valve chamber |4| is a ball valve |45 which is engaged by a stem |46 that is slidably mounted in a suitable bore formed in the plug member |43 and extends upwardly and outwardly thereof through a suitable packing means |41. The outer end of a stem |46 is adapted for engagement with an adjustable nut |49 carried on the adjacent arm of the crosshead member |24. The ball valve |45 is adapted to engage a seat for controlling communication from the chamber |4| to a chamber |52 communicating with the water supply pipe 43, and is adapted to be normally maintained in seated position under the downward force of the spring |25 exerted through the medium of the stem |23, crosshead |24, and valve stem |45. 1

The drain valve assembly |04 is similar in construction to the assembly |03 and comprises a body having a threaded portion |56 disposed within an aperture in the frame |00 and secured in place by means of a lock nut |51. The body |55 has formed therein a valve chamber |58 containing a ball valve |53 which is adapted for engagement with a seat for controlling communication between the chamber and a bore |6| communicating with a drain pipe |62. The ball valve |59 is urged toward the seat |60 under the force of a coil spring |55 disposed in the chamber |58, and is normally held in unseated position, as shown in the drawing, through the medium of a valve stem engaging the -ball valve, which stem extends upwardly through the bore |61 and suitable openings in a plug member |61 and packing |38, and into operative engagement with an adjustable nut |69 mounted on the adjacent end of the crosshead member |24.

Operation The operation of the steam actuated controller device |0 need not be explained in detail, as the functioning of this device is well understood by those skilled in the art, complete description of the mode of operation thereof having been presented in my aforementioned Patents 2,147,294 and 2,176,132. Briefly, when a predetermined maximum pressure of steam is attained in the boiler and in the chamber 64 of the device l0 communicating therewith, the steam pressure becomes effective through the medium of the diaphragm 60 to force the follower member 51 and stem 15 downwardly against the pressure of the spring 68, thereby turning the lever 12 about the bearings 13 for actuating the stems 19 and 50 to move the ball valve 4S away from its seat. Water under pressure is then admitted from the supply pipe 43 past the unseated ball valve 45 and through the restricted passage 45 to the chamber 4| beneath the piston 20, which is thereby shifted upwardly toward its low nre position for operating the valve 33 (see Fig. 1) to restrict the supply of fuel by way of the pipe 3 and for also effecting closure of the draft door 5 and damper 1. As the piston 20 is moved upwardly, the rods 93 and 9| carried by the piston stem 22 are moved in the same direction, the inclined arm 9| causing operation of the bell crank lever 81 to compress the spring 83 and through the medium thereof to exert an upward force on the free end of the lever 12, until the lever is finally returned to its upper position for permitting the spring 48 to seat the ball valve 43, further movement of the elements being then stopped. It will thus be seen that the controller device l0 is operative in accordance with the pressure of steam generated in the boiler to control the furnace fire automatically.

It wil1 be understood, of course, that when the pressure of steam in the chamber 54 acting on the diaphragm 60 is again restored to the normal value, due to the reduction in the rate of steam generation caused by the operation above explained, the spring 68 will then force the follower member 61 and plunger member 'i5 upwardly to relieve the downward pressure on the lever 12, whereupon the spring 54 becomes effective to shift the stems 50 and 19 upwardly until the end 44 of the stem 50 is lifted out of engagement with the ball valve 45, which meanwhile engages its scat. Water under pressure previously supplied to the chamber 4|'is then discharged by Way of the restricted passage 45 and through the passage 5i in the stem to the pipe 5B, from which the Water ovvs by Way of valve chamber |58 of the auxiliary regulator device and past the normally unseated ball valve |53 and through bore |5| to the drain pipe |52.

Referring again to Fig. 1, the weight 28 carriedby the lever 24 then becomes effective to cause movement of the controller device l toward full fire position, and to turn the lever in a clockwise direction about the pin 2t for returning the valve 33 to its normal open position while effecting opening movement of the draft door 5 and of the damper Downward movement of the piston 2i) as just explained is continued until the inclined rod 9| associated therewith permits sumcient clockwise rotation of the bell crank lever 81 about the pin 88 to permit release of the force exerted by the spring 83 against the lever 12, so that the spring 63 is enable to act through the medium of the lever and the valve stems T9 and 50 to effect seating of the end of the stem 50 on the bell valve 45 to stop further draining ofwater from the chamber 4|.

It will be understood that the various elements of the pressure generator I2, the fuel cut-off valve device |8 and the feed water valve device i4 are arranged and proportioned so that the valve 'device i4 will be closed and the valve device I8 opened when the pressure of the fluid maintained in the pipe I6 by the generator corresponds to the normal level of water in the boiler.

Let it now be assumed that the Water in the boiler falls below the normal level, with the result that the pressure of fluid produced by the generator l2 is increased so that the feed water valve device i 4 is operated to supply water to the boiler by way of the pipe l5, while the fuel cut-off valve device I8 is operated'to restrict the flow of fuel to supply pipe 3 and thereby to reduce the rate of supply of fuel to the'burners,

of the furnace With the supply of fuel thus restricted, the rate of generation of steam in the boiler is consequently reduced so that the pressure of steam acting in the chamber S4 of the controller device i3 is gradually lessened, and the operating elements of the controller device are thereby conditioned for automatic movement toward full lire position as hereinbefore explained.

According to the present invention, however, such operationof the steam pressure actuated controller device in response to the reduction in the supply of fuel following the lovv water condition in the boiler is prevented, due to operation of the auxiliary regulator device When the fuel cut-off valve device |8 is automatically operated as above explained to restrict the flow of fuel to the pipe 3, the consequent reduction in the pressure of fuel in the chamber communicating therewith causes upward movement of the diaphragm ||2 and follower member |28 under the force of the spring |25. In so moving the follower member |23 carries with it the stem |23 and crosshead member |24. As the crosshead member |24 is moved upwardly, the spring |55 becomes effective to move the ball valve |59 into engagement with the seat |69 for cutting off the drain communication from the chamber 4| of the controller device I0 through the pipe 56, while with the ball valve relieved 'of dovmwardpressure 'the water underpressuresuppliedithrough the pipe 43 to the chamber A|52 is freeto flow past thelball valve and throughpipe' |42 to the chamber' 4|.

When the crosshead member |24 and associated elements are moved to the extreme upper position, the notch |33'of the latch member |30 is brought into locking engagement with the portion |62 of the frame |80 under the force of the spring |24, and automatic downward movement of the associated elements is'thereby prevented.`

Upon the supply of Water under pressure to the-chamber 4I of the controller device |0 by reason of operation of the auxiliary regulator device as just explained, the piston 20 is moved upwardly, and acts through the medium of the rod 22, and the associated chain and lever elements shown in Fig. 1, to cause movement of the valve device 33 toward its closed position, 4and also to'eiect closing operation of the draft door 5 and the damper 1. The `furnace is thereby conditioned for low re operation.

Upon restoration of thelevel of Water in the boiler to the normal height, the cut-off valve device I8 is once again operated automatically to permit free flow of fuel under pressure to the supply pipe 3, so that the pressure of `fuel in the chamber of the'auxiliary regulator device is restored to the normal value. If -now latch |36 is disengaged from member |02, the diaphragm ||2 is then movedl downwardly and through the medium of the follower member |20 and crosshead member |24 effects movement of the ball valve |45 to seated position while causing vmovement of the ball valve |59y away from its seat, as shown in Fig. 2 of the drawing. The supply `of Water under pressure-through the pipe |42 to the chamber4| of the controller device ID is thus shutoff, while the drain communication is opened to permit discharge of water therefrom byway of the-restricted passage 45, past the ball valve 4B, 'and thence by way of the passage 5|, pipe 56, chamberr |58 and bore I Eil to the drain pipe |62. By reason ofy the restriction in flow of water through the passage 45, the dischargeof water from the chamber 4| iseffected gradually, so that the piston 20 andassociated elements of the controller device Ii! are slowly moved towardfull fire position to prevent too rapid an increase in the supply of fuel tothe furnace.

From the foregoing it Will be seen that the auxiliary regulator device is adapted for association with a furnace and boiler` having automatic control means of the class described and is operative to prevent an increase in the rate of supply of fuel to the furnace following a restriction in the rate of supply of fuel, due to an excessive reduction in the level of the Water in the boiler or otherwise, until the operator releases the latch member |30 to restore the control system to its normal method of operation. The operator thus has an opportunity to ascertain Whether or not the automatic supply of water to the boiler has been accomplished before conditioning the system to increase the rate'of supply of fuel to the furnace. It will be apparent that by reason of the fact that the auxiliary regulator device is simply and inexpensively constructed as a unit, the device is adapted to be employed with different types of boiler control systems, and may be mounted in any suitable position Without the requirement of expensive alterations in existing equipment.

Although one embodiment of the invention has been described in detail, it is not my intention to limit the invention to that embodiment or otherwise than by the terms of the appended claim.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

An auxiliary fuel pressure responsive regulator device adapted for association with an automatic re and draft controller of the type actuated on an increase in iiuid pressure to establish a low fire condition in a furnace, said regulator device comprising a casing having a bracket portion, a spring, a diaphragm mounted within said casing and subject to the opposing pressures of said spring and of fluid fuel supplied to the furnace, a frame member having a flange portion clamped to said casing and a flat portion spaced therefrom, a first valve assembly mounted on said ii'at portion including a supply valve controlling the supply of fluid under pressure to said uid pressure actuated iire and draft controller, a second valve assembly mounted on said iiat portion in spaced parallel relation with respect to said rst assembly and including a release valve controlling the discharge of fluid from said controller, a yoke element operative by said diaphragm and disposed in said frame member with the ends thereof in alignment with the respective valve assemblies, means cooperating with said ends of the yoke element for controlling said. 4release and discharge valves in accordance with movement of said diaphragm, and a latch member pivotally connected to said yoke element intermediate the ends thereof, said latch member being arranged for interlocking engagement with said flat portion of the frame member upon predetermined movement of the associated operating elements.

JAMES W. HARRIE. 

